1. Field of the Invention
The present invention relates to a vertically suspended hung window covering apparatus that improves spacing the way vertical blades or pleats are retrieved.
2. Description of the Prior Art
In the field of interior decoration, there is constant demand for improvements that affect both form and function of a product. Engineered improvements can not only improve the more practical qualities of a product but can have a direct impact on the aesthetic quality of the overall product. Home decorum products such as window blinds that have a functional and decorative aspect will receive notice from scrutinizing professionals and discerning consumers when they operate in a manner that preserves the aesthetic qualities of the product during operation.
Vertical window coverings have become increasingly popular in the interior design and home decorum industry because of their graceful sleek appearance and practical design. From a practical standpoint; vertical blinds are a simple, low maintenance, alternative to drapes, horizontal blinds, and roll blinds. Louver blinds take up little window space when retracted. When deployed, the blinds can be rotated and adjusted to control entry of sunlight. If desired, the window covering can effectively be rotated to block all vision and light through the window. The individual window covering blades can be easily removed, cleaned, and replaced. Such simplicity eliminates the need for professional blind or drape cleaners and reduces maintenance time and expense.
The aesthetic qualities of the louver blinds are also important to its overall commercial success. The louver blinds have attractive parallel lines, evenly spaced window blades. Perhaps the most significant quality of the louver blind is the interaction of sunlight with the blind. Evenly spaced parallel blades create a warm array of sunlight in a room casting a distinct visual pattern of light. Preserving the even spacing during operation and maintaining the orderly visual pattern at all times would be a significant improvement to the art of window coverings.
Vertical blinds from the prior art are described in U.S. Pat. Nos. 4,293,021, 4,316,493, 4,732,202, Re. 33,216, 4,936,370, 4,993,496, and 5,095,966. They are typically suspended from a track that extends across the top of the window. Each track contains several carriers or trucks that conform to the inner dimensions of the track and run along the track. A pulley and rope mechanism typically extends and retracts the trucks. From the truck extends a clasp that holds the window covering blade in place. Most prior art mechanisms have an arrangement for simultaneous rotation of the clasps.
The blades extend the height of the window. They are, when fully deployed, evenly spaced apart. They are of sufficient width to slightly overlap with neighboring blade when rotated to block out the window.
Horizontal displacement of the blinds is typically achieved by a rope and pulley mechanism extending the length of the track. Such a mechanism is illustrated in U.S. Pat. Nos. 4,293,021 and 4,316,493. The rope is fastened to the truck positioned farthest from the parked end of the track called the lead truck. The parked end of the track is the end of the track where the window blades are collected when the blinds drawn to a collected position. When the trucks are pulled from its parked positions they travel a set distance defined by spacers. The respective spacers latch the respective trailing trucks to their respective trailing neighbors. This chain reaction continues until all of the trucks are deployed in spaced relation across the window.
The method of deployment contributes to the attractive design of the blinds. When the blinds are in parked position, they are neatly collected at one side of the window. When some or all of the blinds are deployed across the window, they are uniformly spaced apart. This maintains the attractive visual pattern even when the blinds are in motion.
The blinds are retrieved by pulling the same chord in the direction opposite that for deployment of the blinds. The lead truck is pulled inward and bumps against the next truck and so forth. This causes the blinds being retrieved to successively bunch up together against the blind carried by the lead truck thus destroying the spaced visual pattern established for the central window area by leaving a clump of blinds centrally located in the window.
The unsightly bunching of window blades adjacent the distal truck in the prior art retrieval systems has practical disadvantages. Since the blades congregated farthest from the parked position tend to bind slightly in their travel and present momentum resisting retrieval such, retrieval is unavoidably more difficult thus detracting from the smoothness of operation. Another disadvantage is apparent particularly when the louver blinds cover sliding glass doors. Often, the blinds are retrieved from covering the whole window to covering part of the window to allow persons to walk through the door. Prior art blinds collect the bulk of the blades closest to the central high traffic area making the bulked together blinds most vulnerable to damage or strain.
Engineers and designers in the window covering industry have for many years developed many different variations of the louver blind mechanism. These systems typically deploy the blades across the window to preserve an equally spaced apart repetitive pattern as the blades are deployed. By way of example, see U.S. Pat. No. 4,293,021; U.S. Pat. No. 4,316,493, FIGS. 2-3, No. 26; and U.S. Pat. No. 4,993,469, FIGS. 5-7; The need for even spacing of the blinds is essential to the success of the louver blind. Prior mechanisms typically do not maintain the blinds evenly spaced as they are retrieved from a window covering position to a collected parked position at one end of a track.